Afghanistan's main intelligence agency said Wednesday that Mullah Mohammad Omar, the one-eyed, reclusive supreme leader of the Afghan Taliban, died more than two years ago.

Abdul Hassib Seddiqi, the spokesman for Afghanistan’s National Directorate of Security, said Mullah Omar died in a Pakistani hospital near the city of Karachi in 2013. The Taliban — which has long denied rumors of Mullah Omar's demise — has not yet issued an official statement on the announcement.

​White House spokesman Eric Schultz said "we do believe the reports of his death are credible," but declined to comment further.

The Wall Street Journal reported possible successors include Mullah Akhtar Mansour, the acting head of the Taliban, and Mullah Omar’s son, Mohammad Yacoub, who has taken on a more prominent role in the organization, an unnamed source briefed by Taliban leadership told the publication. The person said that the Taliban leadership was meeting to discuss the transition of power.

Lisa Curtis, an analyst at Heritage Foundation, said it would be hard to replace Mullah Omar because of his stature. “No one has the spiritual authority he had,” she said. There are no prominent leaders within the Taliban that are natural successors, she said.

She said reports of his death have caused further disarray within the ranks and could lead to defections to the Islamic State, which is trying to make inroads in Afghanistan and Pakistan.

The lack of leadership does not seem to have weakened the Taliban’s operations throughout the country over the past year, said Anthony Cordesman, analyst with Center for Strategic and International Studies. Taliban militants have launched attacks in south and north parts of the country, attempting to capitalize on the drawdown of U.S. and coalition forces. That could reflect regional Taliban commanders operating on their own initiative, Cordesman added.

It was unclear why Mullah's Omar death was only being confirmed now, but it comes just days before the start of another round of peace talks between the Afghan government and the Taliban aimed at ending nearly 14 years of fighting.

The Journal said divisions within the Taliban, particularly over the peace talks, and questions about who is leading the group may have finally provoked the admission Mullah Omar was died.

Earlier this month, the Taliban issued a message justifying the peace talks and attributed it to Mullah Omar to mark the Muslim festival of Eid al-Fitr.

Mullah Omar's leadership appeared to unify the Taliban and confirmation of his death could complicate peace talks if members split on whether to continue their insurgency or enter into a cease-fire agreement.

In April, the Taliban published a 5,000-word biography of Mullah Omar online to mark his 19th year as their supreme leader. An extract of the biography said that despite being "regularly tracked by the enemy, no major change and disruption has been observed in the routine works of (Mullah Omar) in ... organizing the jihadi (holy war) activities as the leader of the Islamic Emirate," according to Al Jazeera.

Mullah Omar is believed to have been living in the cities of Quetta and Karachi in Pakistan since the Taliban was toppled by a U.S.-led invasion in Afghanistan in 2001, Afghan broadcaster TOLOnews reported. The U.S. toppled the regime for giving safe haven to al-Qaeda leader Osama Bin Laden ahead of the 9/11 terror attacks.

The U.S. State Department had put a $10 million bounty on Mullah Omar's head.

Pakistani newspaper The Express Tribune reported a former Afghan Taliban minister and current leadership council member, who spoke on condition of anonymity, said Mullah Omar died from tuberculosis. The ex-minister added that Omar's son had identified the body, and that he was buried in Afghanistan, the Tribune reported.